Hello Murali,
I agree with CB above, again Specificaiton IDOC can have more than 4000 segment which will take lot of time to move between client,
If intent is to reduce the time -
Move the specifciation via multiple approch - Spec which does not have more data such as LN_UN_SUB, DG_CL_SUB via .dat file (simple export and import function) than one with lot of data such as Real Sub use ALE,
If you are using any data load Program such as Data editor or BAPI this may be more faster.
try comparing the time to move the data via .dat file or ALE you will see a pattern which will help to reduce the time.
Hope this helps.
Gopi